The introduction of wireless field devices into the process industry presents new technical challenges when these devices are used in closed loop control. This presentation will address how the traditional PID positional and velocity algorithms may be restructured as PIDPlus to use the slow, non-periodic measurement updates of a wireless transmitter. A combination of event triggered and periodic execution is used to address control of faster processes such as liquid and gas flow using wireless transmitters and wireless valves. Examples are used to demonstrate how this capability has been incorporated into commercial control systems. Information will be provided on the control performance achieved in field applications using wireless transmitters and/or wireless throttling valves. Future areas of event driven control in the process industry, in particular MPC control using wireless measurements, will be outlined as well.
Emerson, Austin, TX
Mark Nixon has been involved in the design and development of control systems throughout his career. Mark started his career as a systems engineer working on projects in oil & gas, refining, chemicals, and pulp & paper. He moved from Canada to Austin, TX in 1998 where he has held a variety of positions in both research and development. From 1995-2005, Mark was lead architect for DeltaV.
In 2006, he joined the wireless team, taking a very active role in the development of the WirelessHART specifications and the development of the IEC 62591 standardization. Mark’s current research includes control using WirelessHART devices, data analytics for batch process, use of wireless technology the process industry, mobile users, operator interfaces, and advanced graphics. He is currently active in the Center for Operator Performance, WirelessHART, ISA-88 standard, Foundation Fieldbus standards, and ISA-101 standard. He has written numerous papers and currently holds more than 45 patents. He co-authored WirelessHART: Real–Time Mesh Network for Industrial Automation and has made contributions to the Industrial Instruments and Controls Handbook and Essentials of Modern Measurements and Final Elements in the Process Industry. Mark is an ISA Fellow as well.